CZ20031583A3 - Elevator and traction sheave thereof - Google Patents

Abstract

A counterweight and an elevator car are suspended on a set of hoisting ropes, the hoisting ropes being steel wire ropes or having a load-bearing part twisted from steel wires. The elevator comprises one or more rope pulleys provided with rope grooves, one of said pulleys being a traction sheave driven by a drive machine and moving the set of hoisting ropes. At least one of the rope pulleys is provided with a coating bonded to the rope pulley and containing the rope grooves, said coating having a thickness that, at the bottom of the rope groove, is substantially less than half the thickness of the rope running in the rope groove and a hardness less than about 100 shoreA and greater than about 60 shoreA. In a preferred solution, the traction sheave is a rope pulley like this.

Description

Lift and traction sheave lift

Technical field

The present invention relates to an elevator as defined in the preamble of claim 1 and to a traction sheave of an elevator as defined in the preamble of claim 7.

BACKGROUND OF THE INVENTION

The operation of a conventional traction sheave elevator is based on a solution in which the steel ropes serving as hoisting and suspension ropes are advanced by means of a metal traction sheave, often made of cast iron, driven by the elevator drive machine. The movement of the hoisting ropes creates the movement of the counterweight and the elevator car suspended from them. The pulling force from the traction sheave to the hoisting ropes, as well as the braking force applied by the traction sheave, are transmitted by friction between the traction sheave and the ropes.

The coefficient of friction between wire ropes and metal traction sheaves used in elevators is often insufficient to maintain the desired grip between the traction sheave and the hoisting rope itself in normal situations during elevator operation. The friction and forces transmitted by the rope are increased by adjusting the shape of the rope guide grooves on the traction sheave. The traction sheaves are formed with cut rope or V-shaped grooves, which create stresses and strains on the hoisting ropes and therefore also cause more wear on the hoisting ropes than the rope grooves with a preferred semicircular cross-sectional shape as used, for example in deflection pulleys. The force transmitted by the rope can also be increased by increasing the angle of engagement between the traction sheave and the ropes, for example using a so-called double-wrap arrangement.

In the case of a steel rope and a traction sheave of cast iron or cast steel, a rope grease is almost always used to reduce rope wear. In particular, the lubricant reduces the internal wear of the rope resulting from the interaction between the rope strands. The outer wear of the rope consists of wear on the surface strands, which is mainly caused by the traction sheave. The effect of the lubricant is also significant in contact between the rope surface and the traction sheave.

To provide a replacement for the shape of the rope guide groove that causes the rope to wear, inserts inserted into the rope guide groove are used to achieve a greater coefficient of friction. Such prior art inserts are described, for example, in US3279762 and US4198196. The pads described in these documents are relatively thick. The guide grooves for the ropes with the inserts are formed with a transverse or almost transverse ripple creating additional elasticity in the surface portion of the insert, thereby softening its surface. The inserts undergo wear due to the forces exerted on them by the ropes, so the inserts must be replaced at certain intervals. The inserts wear in the cable guide grooves at the interface between the insert and the traction sheave and inside the insert.

It is an object of the present invention to provide an elevator in which the traction sheave has an excellent grip on the steel cable and in which the traction sheave is durable and has a construction that reduces rope wear. Another object of the present invention is to eliminate or eliminate the above-mentioned disadvantages of the prior art solutions and to provide a traction sheave that provides excellent grip on the rope and is durable and reduces rope wear. A specific object of the present invention is to propose and describe a new type of engagement between a traction sheave and a rope in an elevator. It is also an object of the present invention to apply said engagement between the traction sheave and the rope for possible deflection pulleys of the elevator.

SUMMARY OF THE INVENTION

The features of the present invention are defined in the appended claims.

In an elevator formed with hoisting ropes of substantially circular cross-section, the direction of deflection of the hoisting ropes can be freely changed by means of a pulley. Thus, the basic layout of the elevator, i.e. the location of the car, counterweight and ^{5 of the} hoist, can be changed relatively freely.

Steel ropes or ropes, formed with a load carrying part twisted from steel strands, represent a tried and tested method of assembling a set of hoisting ropes for suspending an elevator car and counterweight. Elevator, driven by the traction sheave ⁰ may comprise other diverting pulleys besides the traction sheave. The deflection pulleys are used for two different purposes: the deflection pulleys are used to create the desired suspension ratio of the elevator car and / or counterweight, and the deflection pulleys are used to guide ⁵ the rope path. Each deflection pulley may be predominantly used for one of these purposes or may have a particular function, both with respect to the suspension ratio and with respect to use as a rope guiding means. In addition, the traction sheave, driven by the driving machine, moves the set of hoisting ropes.

⁰ The traction sheave and other deflection pulleys, if any, are formed with guide grooves for the ropes, with each rope in the set of hoists. the ropes are guided separately.

When the rope pulley has a rope guide grooves provided with a coating and providing high friction against the steel cable, virtually non-slip contact between the rope pulley and the rope is achieved. This is particularly advantageous when the rope pulley is used as a traction sheave. If the coating is relatively thin, the force difference resulting from the differences between the rope forces acting on different sides of the pulley will not produce a large tangential displacement of the surface, which would lead to a large extension or compression in the pulling direction as the rope enters or leaves the pulley. The biggest difference on the pulley is with the traction sheave, which is due to the usual weight difference between the counterweight and the elevator car and the fact that the traction sheave is not a free-rotating pulley but creates at least during acceleration and braking a factor of the rope forces resulting from the balance difference, depending on the direction of the balance difference and the direction of movement of the lift. The thin coating is also advantageous in that, when compressed between the rope and the traction sheave, the coating cannot be compressed so much that such compression would tend to unfold to the sides of the rope guide groove. Such compression would cause lateral expansion of the material, and the coating could be damaged by the high stresses created therein. However, the coating must have a thickness sufficient to accommodate the tension elongation of the rope, so that there is no slippage of the rope causing the coating to fray. At the same time, the coating must be soft enough to allow the structural unevenness of the rope, in other words to the surface strands, to at least partially submerge the rope.

into the upholstery, while still being sufficiently hard to ensure that the upholstery does not leak significantly from the unevenness of the rope.

For steel wire ropes less than 10 mm thick, in which the surface strands have a relatively small thickness, the hardness of the coating that can be used ranges from less than 60 Shore to about 100 Shore. For ropes having surface strands thinner than conventional elevator ropes, i.e. ropes having surface strands only about 0.2 mm thick, the preferred coating hardness is in the range of about 80 to 90 Shore or greater. The relatively hard coating can be made thin. When a rope with somewhat thicker surface strands (about 0.5 to 1 mm) is used, the hardness of a suitable coating is in the range of about 70 to 85 according to Shore and a thicker coating is needed. In other words, a thicker and thinner coating is used for thinner strands and a softer and thicker coating is used for thicker strands. Since the coating is rigidly attached to the traction sheave by means of an adhesive bond covering the entire surface resting against the traction sheave, there will be no slippage between the coating and the traction sheave, causing them to wear out. The adhesive bond may be formed, for example, by vulcanizing a rubber coating on the surface of a metal traction sheave or by casting a polyurethane or similar coating material on a traction sheave with or without glue or applying the coating material to the traction sheave.

Thus, on the one hand, due to the total load or the average surface pressure applied to the rope coating, the coating should be hard and thin, and on the other hand, the coating should be soft and strong enough to allow unevenness.

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B «to the surface structure of the rope to immerse in the coating to an appropriate extent to create sufficient friction between the rope and the coating and to ensure that an uneven surface structure does not break through the coating.

A very preferred embodiment of the present invention is the use of a traction sheave coating. Thus, a preferred solution is to provide an elevator in which at least the traction sheave is formed with a coating. The coating is also preferably used on the elevator deflection pulleys. The coating acts as a cushioning layer between the metal pulley (rope pulley) for the rope and the hoisting ropes.

The traction sheave coating and the rope pulley coating may be differently formed such that the traction sheave coating is designed to receive a larger sheave. Properties that are the thickness and material properties of the coating. Preferred coating materials are rubber and polyurethane. It is desired that the coating be elastic and durable, so that other durable and elastic materials may be used as long as these materials can be made strong enough to withstand the surface pressure exerted by the rope. The coating may be formed with reinforcements, such as carbon fibers or ceramic or metal fillers, to improve its ability to withstand internal stresses and / or wear, or to improve other properties of the surface of the coating that faces the rope.

The present invention provides, inter alia, the following advantages:

the large friction between the traction sheave and the lifting force difference to be determined are the rope;

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The coating reduces wear by abrasion of the ropes, which means that less wear is needed on the surface strands of the rope, so that the ropes can be made entirely of thin strands of solid material;

since the ropes can be made of thin strands and since the thin strands can be made relatively stronger, the hoisting ropes can be correspondingly thinner, smaller rope pulleys can be used, which again allows for space savings and a more economical overall layout;

the coating is durable because there is no large internal expansion in the relatively thin coating;

in a thin coating, deformations are small and therefore also the ₁₅ loss resulting from deformations and producing heat within the coating is low and heat is easily removed from the thin coating, so the thermal strain produced in the coating load is small;

since the rope is thin and the coating on the rope pulley 20 is thin and hard, the rope pulley slightly rolls against the rope;

there is no wear of the coating at the interface between the metal traction sheave section and the coating material;

the high friction between the traction sheave and the hoisting rope 25 allows the elevator car and counterweight to be made relatively light, which means cost savings.

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In the following, the present invention will be described in detail by way of example embodiments with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 shows a diagram representing an elevator according to the present invention;

Giant. 2 shows a rope pulley utilizing the present invention;

Fig. 3a, Fig. 3b, Fig. 3c and Fig. 3d show various alternative coatings and rope pulleys; and

Giant. 4 illustrates another coating solution for the present invention.

Examples of embodiments of the invention although presented for lifts are also provided

Giant. 1 is a schematic representation of an elevator structure. The elevator is preferably an elevator without machine room, in which the drive machine 6 is located in the elevator shaft, the invention is of course applicable to the machine room. The path of the hoisting ropes 3 of the elevator is as follows: one end of the ropes is fixedly fixed to the anchor 13 located in the upper part of the shaft above the path of the counterweight 2 moving along the counterweight guide rails 11. The deflection rollers 9 are rotatably mounted on the counterweight 2 and from there the ropes 3 extend further up to the traction sheave 7 of the driving machine 6, passing along the traction sheave along the traction sheave guide grooves. From ϊϊ ..

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AAAA AA traction sheaves 2 extend the ropes 2 further down to the elevator car 2 'which moves along the carriage rails 10, passing below the cabin via the deflection pulleys 4 used to suspend the elevator car on the ropes and then sweeping upwards from the elevator car to anchor 14 in the upper part of the elevator shaft, the other end of the ropes 3 being attached to this anchorage. The anchor 13 in the upper part of the shaft, the traction sheave 7 and the deflection rollers 9 hanging the ropes are preferably so positioned relative to each other that The ropes extending from the anchor 13 to the counterweight 2, as well as the portion of the ropes extending from the counterweight 2 to the traction sheave 7, are substantially parallel to the expensive counterweight 2. Similarly, it is also preferred that the anchor 14 at the top of the shaft, the traction sheave 7 and the deflection pulleys 6 suspending the elevator car to the ropes are arranged relative to each other such that the ropes extending from the anchor 14 to the elevator car 1, and the part of the ropes extending from the elevator car 1 to the traction sheave 7 are substantially parallel to the path of the elevator car 2; ^with this arrangement, no further deflection pulleys are required to define the path of the ropes in the shaft. The rope suspension acts substantially centrally on the elevator car 2 while ensuring that the rope pulleys carrying the elevator car are mounted substantially symmetrically with respect to the vertical center line passing through the center of gravity of the elevator car 2. The driving machine 6 located in the elevator shaft preferably has a flat construction in other words, the machine has a small depth as compared with its width and / or height, or at least the machine is slim enough to be accommodated between the elevator car ³⁰ and a wall of the elevator shaft. The machine can be ·· 4 ·· 4

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4 »44 44 44 44 also stored differently. In particular, the slim machine can be mounted relatively easily above the elevator car. The elevator shaft may be provided with the equipment required to supply power to the traction sheave motor 2 ^as well as the elevator control equipment, both of which may be located in a common dashboard 8 or mounted separately from each other or integrated partially or wholly with the drive machine 6 .. The drive machine can be with or without gears. A preferred solution is a gearless machine that includes a permanent magnet motor. The drive machine may be attached to the wall of the elevator shaft, to the ceiling, to the guide rail or guide rails, or to some other structure, such as a beam or frame. In the case of a lift with a drive machine at the bottom, another option is to mount the machine to the bottom of the elevator shaft. Giant. 1 illustrates an economical 2: 1 suspension, but the invention can also be implemented in an elevator using a 1: 1 suspension ratio, in other words, an elevator in which the hoisting ropes are connected directly to the counterweight and elevator car without deflection pulleys or some other suspension arrangement suitable for a traction sheave elevator.

Giant. 2 is a partial cross-sectional view of a rope pulley 100 utilizing the present invention. The rope guide grooves 101 are in the cover 102 mounted on the rim of the rope pulley. The pulley is preferably made of metal or plastic. A bearing space 103 is provided in the pulley head used to support the pulley. The pulley is also provided with bolt holes 105, which allows the pulley to be secured with its side to be anchored in a drive machine 18, for example to a rotating flange, to form a traction sheave 7, 9 «999

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Giant. Figures 3a, 3b, 3c and 3d illustrate alternative pulley coating methods. An easy way with respect to manufacturing techniques is to create a smooth cylindrical outer surface of the pulley, as illustrated in Fig. 3d, with a coating 102 in which the rope guide grooves 101 are formed. Such a grooved coating made on a smooth surface as illustrated in Fig. 3d, but cannot withstand the very high pressure exerted by the ropes as they are pressed into the rope guide grooves, since this pressure can spread laterally. In the solutions shown in Fig. 3a, Fig. 3b and Fig. 3c, the shape of the rim is better adapted to the shape of the rope guide grooves in the coating so that the shape of the rope guide grooves is better supported and the load bearing layer of uniform or nearly uniform thickness below. rope provides better resistance to lateral spreading of pressure stresses created by ropes. The lateral expansion of the coating due to pressure is supported by the thickness and elasticity of the coating and limited by the hardness and possible reinforcements of the coating. In particular, in the solution illustrated in Fig. 3c, in which the coating has nearly half the rope thickness, a hard and non-elastic coating is needed, whereas the coating of Fig. 3a, which has a thickness equal to approximately one tenth of the rope thickness, softer. The thickness of the coating in Fig. 3b at the bottom of the groove is approximately one-fifth of the thickness of the rope. The thickness of the coating should be at least 2 to 3 times the texture depth of the rope surface, which consists of rope strands ovými Such a very thin coating having a thickness even less than the thickness of the rope strand does not necessarily withstand the stresses exerted on it. IN

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In practice, the coating must have a thickness greater than this minimum thickness since the coating will also have to accept rope surface changes that are more uneven and coarser than the surface texture. Such a coarser region is formed, for example, where the differences in the level between the tangles of the rope are greater than the differences between the strands. In practice, a minimum coating thickness of about 1 to 3 times the thickness of the surface strand is suitable. In the case of ropes commonly used in lifts that have been designed to come into contact with a metal rope groove and have a thickness of 8 to 10 mm, this definition results in a coating of at least about 1 mm in thickness. As the traction sheave coating, which causes more rope wear than other rope pulleys in the elevator, will reduce rope wear and thus also reduce the need to produce ropes with strong surface strands, the ropes can be made smoother. The use of thin strands allows the rope itself to be made thinner, since thin steel strands can be made of a stronger material than thicker strands. For example, using strands of 0.2 mm thickness, a 4 mm elevator lift rope of relatively good construction can be formed. However, the coating should be strong enough to ensure that it is not easily scraped off or punctured, for example, by a possible grain of sand or the like that gets between the rope guide groove and the hoisting rope. Thus, the required minimum coating thickness, even if thin strand hoisting ropes are used, should be approximately 0.5 to 1 mm.

Giant. 4 represents a solution in which the rope guide groove 201 is in a coating 202 that is thinner at the sides of the guide groove than at the bottom. In such a solution, the coating is embedded in

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4 44 44 4 4 4 základní base grooves 220 formed in the rope pulley 200, so that the deformations created in the coating by the pressure exerted on it by the rope will be small and predominantly limited to the surface texture of the rope immersed in the coating. Such a solution often means in practice that the pulley coating consists of mutually separated sub-coatings specific for the guide groove. It is naturally also possible to use guide-slot-specific sub-coatings in the solutions presented in Figs. 3a, 3b and 3c.

In the foregoing, the present invention has been described by way of example with reference to the accompanying drawings, but of course different embodiments of the invention are possible and are also within the scope of the inventive idea as defined in the appended claims. Accordingly, it is also evident that the thin rope increases the average surface pressure exerted on the rope guide groove as long as the ropes remain unchanged. This can easily be taken into account by adjusting the thickness and hardness of the coating, since the thin rope has thin surface strands, so that, for example, the use of a harder and / or thinner coating will not cause any problems.

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Claims (8)

An elevator in which the counterweight and the elevator car are suspended from a set of hoisting ropes consisting of hoisting ropes of substantially circular cross-section and comprising one or more rope pulleys formed with rope guide grooves, one of said pulleys being a traction sheave driven by a driving machine and a movable set of hoisting ropes, characterized in that at least one of said rope pulleys has a coating against the hoisting ropes adhesively fastened to a rope pulley and comprising rope rope grooves, said coating having a thickness a rope guide groove bottom substantially less than half the thickness of the rope passing through the rope guide groove, and a hardness less than about 100 Shore and greater than about 60 Shorea. Elevator according to claim 1, characterized in that a traction sheave is formed with the coating. Elevator according to claim 1, characterized in that all rope pulleys are provided with the covers. Elevator according to claim 1, characterized in that the coverings on the traction sheave and on the at least one other rope pulley differ from each other. Elevator according to any one of the preceding claims, characterized in that the thickness of the coating varies in the width direction of the rope guide groove on the rope pulley. Elevator according to any one of the preceding claims, characterized in that the hoisting ropes have a load carrying part twisted from steel strands. 9 · • 9 9 9 9 9 9 9 9 · 9 9 9 9 9 9 9 98 99 * · · * ·> 9 9 9 9 9 9 9 9 99 99 Ί. A traction sheave of an elevator designed for hoists of substantially circular cross-section, characterized in that the traction sheave has a coating against the hoisting ropes adhesively fastened to the traction sheave and comprising rope guide grooves, 5, the coating has a thickness that is substantially less than half of the thickness of the rope passing in the rope guide groove at the bottom of the rope guide groove and a hardness of less than about 100 Shore and greater than about 60 Shore. A traction sheave according to claim 7, characterized in that the coating is thinner in the outer regions of the rope guide groove than at the bottom of the rope guide groove. The traction sheave according to any one of claims 7 to 8, characterized in that the coating is made of rubber, polyurethane or some other elastic material. The traction sheave according to any one of claims 7 to 9, characterized in that the coating thickness is at most about 2 mm.